Yep, upgrading RAM works the same as in the old days.
If you want to make a backup, I highly recommend using Samsung Recovery. It can makes a bootable backup of the recovery partition in case you want to restore the machine to its factory state at some point. You'll need a 32 gig USB flash drive in my experience, even though the backup uses around 16 gigs (it will fail with a 16 gig flash drive but works fine with a 32 gig drive).
If you want to install Windows 8 Pro rather than the OS image that came with the machine, I wouldn't recommend using a restore function afterward because you'll get driver mismatches and there are differences between Win 8 Home Premium that comes with the machine and Win 8 Pro. Just back up your personal files instead and plan on re-installing any apps you've added. You'll want to download Samsung Update from their website: that's the app that downloads all the drivers and if you like it can also reinstall the bundled programs (you can pick and choose among the apps).